1. Technical Field
This disclosure relates generally to lubricating a component of a rotational system such as, for example, a turbine engine.
2. Background Information
A turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Some turbine engines may also each include a gear train, which rotationally couples and transmits torque between a rotor of the turbine section and a rotor of the fan section. Such a gear train may include a plurality of gears and a plurality of journal bearings. The gears are rotatably supported by the bearings, and rotationally couple and transmit torque between the turbine rotor and the fan rotor.
When the turbine engine is powered up, a lubrication system for the turbine engine may lubricate the bearings of the gear train. For example, a forward rotating engine shaft may mechanically drive a pump to direct lubricant from a reservoir to the bearings. Such a mechanically driven pump, however, cannot direct lubricant to the bearings when the engine shaft is rotating in a reverse direction. Rather, the reverse rotating engine shaft may drive the pump to siphon air and/or lubricant from the bearings. Such reverse rotation may occur, for example, where the turbine engine is powered down and wind is blowing into a bypass gas path nozzle of the turbine engine causing the fan rotor to windmill in the reverse direction.
To prevent the unlubricated bearing of the gear train from seizing during reverse rotation, the turbine engine may be configured with a mechanical rotor lock. Such a rotor lock, however, may increase cost and complexity of the turbine engine. In addition, if the rotor lock is mistakenly left unengaged or fails, the unlubricated bearings of the gear train may still be susceptible to seizing.
There is a need in the art for an improved lubrication system for a turbine engine.